The river San Juan de Nicaragua directly connects the Atlantic with the south end of the lake of the above name, from the northern end of which but a few miles intervene to the Pacific. Various surveys have been made of the river, with a view to the construction of a canal. In 1837-8 Lieutenant Baily[206] was employed by the Central American Government to explore the route. He found that the surface of the lake of Nicaragua is 121 feet 9 inches above low water in the Atlantic. The river San Juan, in its course of 79 miles from the lake, varies in depth from 9 feet to 20 feet, and its course is broken by various rapids, some of which are of considerable length. The summit-level of the mountain chain which divides the valley of the lake from the Pacific is 487 feet above the lake, and a tunnel of nearly 16 miles long would have to be pierced through this wall in order to reach the port of San Juan del Sur on the Pacific. The total length of navigation, through river, lake, and canal, according to Mr. Baily’s plans, would be 190 miles. The port of San Juan del Sur is narrow at the entrance, but widens within the harbour. It is surrounded by high land, except from W.S.W. to W. by S. The depth of water at the entrance is 3 fathoms, and the width 1100 yards. Ships could thence go up for a mile and a half, but the amount of excavation required for a canal 30 feet deep and 50 feet wide was estimated at not less than 162 million cubic yards, which has been stated to be more than that required for the construction of 2000 miles of English railway—a figure quite conclusive against this scheme. In 1852 the route was surveyed by Colonel Childs,[207] who proposed to descend from the lake by fourteen locks to Brito, on the Pacific, where, however, there was no harbour. The length of this route was given as 194 miles. To avoid the difficulty of cutting through the ridge, it has been proposed to continue the navigation from the extreme north of the Lake of Nicaragua, by the Estero de Panaloya and the river Tipitapa to the Lake Leon, or Managua, and thence to the port of Realejo, on the Pacific, or, yet more to the north, to the Estero Real, an arm of the Gulf of Fonseca. But it has been pointed out that the length of the navigation would thus be increased by a hundred miles, and it is doubtful whether Lake Leon could furnish the water necessary for lockage, in both directions, which it would have to supply. The Nicaragua route, therefore, whatever may be its advantages, if any, over that of Panama, is liable to the objections of great length, large works, numerous locks, and the no less formidable danger, to use the words of Humboldt, that “there is no part of the globe so full of volcanoes as this part of America, from the 11th to the 13th degrees of latitude.”[208]